Alrighty, I have a 1999 Durango SLT 4x4, 360 V8 5.9L throttle body.

The vehicle has always been a hard starter but now I have a 'crank but no start' issue with it.

A little history, a few months ago the vehicle started but would not stay running without revving the motor. I ended up replacing the Idle Air Control and that appeared to fix the problem.

A couple of weeks later it started doing the same thing, started but wouldn't stay running without revving the motor. I replaced the Throttle Position Sensor and this again appeared to solve the issue.

Then when the cold weather really hit it would do it on and off again but corrected itself after a couple of hours. It would then start and run no problems for a couple of weeks.

About a month ago the belt tensioner and idler pulley went out and I replaced those.

Now it's crank but no start.

So thus far I've:

1. Replaced the IAC
2. Replaced the TPS
3. I have spark from the coil to the plugs so it's probably not the PCM (but I could be wrong). Used a Lisle spark tester set at 0.40
3a. Replaced the distributor cap and rotor for farts and giggles (needed it anyways).
4. I have 55 pounds of pressure through the fuel rail. This would indicate the fuel pump and fuel pressure regulator are operational, correct?

So this leaves me with:
1. Is the belt tensioner somehow tied in with the timing and did replacing the tensioner somehow effect the timing? The truck ran for about two weeks after replacement.
2. Crankcase sensor?
3. Starter, even though not grinding?
4. Manifold Absolute Pressure sensor?
5. Possibly the Cold Air Intake?

Thank you for any assistance.

 

The belt has nothing to do with timing, so that isn't an issue. I'd clean the battery terminals really well, and if you battery is old it should probably be replaced. A weak battery or poor connection to the battery can screw with the computer and cause weird issues like it not wanting to idle or start easily.

 

Battery is less than a year old and connections are solid.

 

Even if they look clean they can still have that clear glassy corrosion on them. Make sure you check where the wires themselves clamp onto the connectors, where they connect to the PDC, and where they connect to the body and block.

 

You never said that you cleaned the TB, including the area by the IAC. I'd also consider plugs/wires/cap/rotor. I'd check the fuel pressure too. I'm not sure to what extent the ECU already does that.

 

Correction on the fuel pressure.

When just priming the fuel pump, it goes to 30 lbs and then immediately drops to 0.

When cranking the pressure reads at 50-55 lbs, but when stopped the pressure immediately drops to 0.

 

There is a check valve that is supposed to keep the pressurized fuel form draining back into the tank, but it sounds like that isn't working. I'm not sure that would keep it form starting though. The check valve on mine is going bad because fuel pressure does slowly bleed off back into the tank, so I usually turn the key to on, let the fuel pump run, then turn the key off, back to on, let the pump run again, then start.

 

Ordered a scanner, will be here on Wednesday. Poured some gas down the throttle body and it did not fire up.

Thoughts?

 

Any P codes? You don't need a scanner to see. Key on-off-on-off-on, read the odometer.

 

I have a few: https://dodgeforum.com/forum/1st-gen...-no-spark.html

And take that Throttle Body off and use 2 cans of Throttle Body cleaner and an old tooth brush on it. Clean out every orifice. Reset the PCM and see if she starts.

+1 Fuel pump check valve is bad.

There is a timer built into the PMC that tells the fuel pump to shut down after about 2 seconds without the engine running. It's a safety in case of an accident so the pump doesn't continue to pump fuel all over.